Silicates are well characterised in the literature, for example `The Chemistry of Silica` by R. K. Iler (published by Wiley Interscience 1979), and they have a number of applications as binders Examples of these applications are in sand moulding for metal casting, protective coatings, sealants, adhesives and as welding rod binders.
In the latter application the silicate binder is required to provide mechanical strength to the formulation around the metal core and have a satisfactory moisture resistance.
Additionally, the effect of binder composition on the evolution of chromium fumes during welding has been described by Kimura et al in a paper presented to the American Welding Society in April 1979 and published in Welding Research Supplement July 1979 The chromium fumes can arise from both the substrate and rod and Kimura demonstrated that reducing the sodium and potassium level in the water soluble binder component leads to a reduction in evolution of chromium fumes while the presence of lithium did not lead to chromium evolution. Thus there is an advantage in using only lithium silicate as the rod binder.
A general background description of welding can be found in Kirk Othner (pub Wiley & Son 1970) vol 22 pages 241 to 252. Although the term welding `rod` is used herein it will be understood that the welding electrode used may have a shape other than the geometric rod.